In blasting operations, detonators and explosives are buried in the ground, for example, in holes (e.g., bore holes) drilled into rock formations, etc., and the detonators are wired for external access to blasting machines that provide electrical firing signaling to initiate detonation of explosives. Wireless blasting involves use of a remotely located master controller and a local slave wireless device connected to a blasting machine at the blast site, with the blasting machine being wired to an array of detonators. In wireless blasting systems, no wiring or lead lines are connected between the detonator array and the master controller, and the master controller can be positioned a significant distance from the blast site, such as 1-5 miles in one example. The blasting machine is normally turned on together with the slave controller as the operator walks from the blast area to the master controller site some distance away, where the blast sequence includes power up, verification and/or programming of delay times, arming and finally issuance of a “fire” command. The blasting machine provides sufficient energy and voltage to charge the firing capacitors in the detonators, and initiates the actual detonator firing in response to the fire command. During the firing phase, upon operator input at the master controller, a fire command is transferred from the master to the slave which then issues the final command to the blasting machine in order to fire the detonator array. Accordingly, improved techniques, systems and apparatus are desirable for improved safety in wireless remote blasting.